A power management integrated circuit PMIC is a power supply device for supplying electrical power to different subsystems of an electronic device. In general, the PMIC controls the power flow from an energy source (such as e.g. a wall plug charger, a battery, or a supercapacitor) to the respective subsystems. At this, it is the task of a PMIC to meet the voltage and current requirements of the subsystems, or to reduce the overall power consumption of the electronic device. The PMIC may comprise e.g. voltage regulators or overcurrent detectors for protecting both the individual subsystem as well as the PMIC itself.
Examples for subsystems of an electronic device which may be powered by a PMIC include e.g. processing units such as microprocessors, digital signal processors DSP, application-specific integrated circuits ASICs, field programmable gate arrays FPGAs, storage units such as volatile or non-volatile memory units, input/output devices such as e.g. touchscreen displays, battery chargers, display subsystems e.g. for LCD display back lighting, LEDs, wireless radios, sensor units such as acceleration sensors or temperature sensors, or digital cameras.
The PMIC is fully autonomous. It is typically the first system device powered on and the last device powered off. Configuration data of the PMIC may be held in non-volatile memory. The PMIC may serve as power supply for all subsystems of an electronic device. For this purpose, PMICs may execute finite state machines for controlling the power states of the subsystems and typically include power state control circuitry for power-up and power-down sequencing and system status monitoring. Multiple active power states may exist. Based on external or internal triggers, the PMIC may control power sequencing and transitions between different power states.
The system monitoring function of a PMIC may include voltage, current and temperature monitoring. In addition, the system status monitoring may include post processing functionality like e.g. conversion and aggregation of analog-to-digital conversion ADC samples over a period of time. In other words, the PMIC may keep a history about recent values of the system status and power supply to a subsystem may be based on said history.